Environmental factors and host sex influence the skin microbiota structure of Hong Kong newt (Paramesotriton hongkongensis) in a coldspot of chytridiomycosis in subtropical East Asia.

Chytridiomycosis, an infectious skin disease caused by the chytrid fungi, Batrachochytrium dendrobatidis and B. salamandrivorans, poses a significant threat to amphibian biodiversity worldwide. Antifungal bacteria found on the skin of chytrid-resistant amphibians could potentially provide defense against chytridiomycosis and lower mortality rates among resistant individuals. The Hong Kong newt (Paramesotriton hongkongensis) is native to East Asia, a region suspected to be the origin of chytrids, and has exhibited asymptomatic infection, suggesting a long-term coexistence with the chytrids. Therefore, the skin microbiota of this resistant species warrant investigation, along with other factors that can affect the microbiota. Among the 149 newts sampled in their natural habitats in Hong Kong, China, putative antifungal bacteria were found in all individuals. There were 314 amplicon sequence variants distributed over 25 genera of putative antifungal bacteria; abundant ones included Acinetobacter, Flavobacterium, and Novosphingobium spp. The skin microbiota compositions were strongly influenced by the inter-site geographical distances. Despite inter-site differences, we identified some core skin microbes across sites that could be vital to P. hongkongensis. The dominant cores included the family Comamonadaceae, family Chitinophagaceae, and class Betaproteobacteria. Moreover, habitat elevation and host sex also exhibited significant effects on skin microbiota compositions. The antifungal bacteria found on these newts offer an important resource for conservation against chytridiomycosis, such as developing probiotic treatments for susceptible species.

Using quality improvement approaches to increase emergency department provider engagement in research participant enrollment during COVID-19 and opioid overdose public health emergencies.

PURPOSE: We utilized quality improvement (QI) approaches to increase emergency department (ED) provider engagement with research participant enrollment during the opioid crisis and coronavirus disease (COVID-19) pandemic. The context of this work is the Evaluating Microdosing in the Emergency Department (EMED) study, a randomized trial offering buprenorphine/naloxone to ED patients through randomization to standard or microdosing induction. Engaging providers is crucial for participant recruitment to our study. Anticipating challenges sustaining long-term engagement after a 63% decline in provider referrals four months into enrollments, we applied Plan-Do-Study-Act (PDSA) cycles to develop and implement an engagement strategy to increase and sustain provider engagement by 50% from baseline within 9 months. METHODS: Our engagement strategy was centered on Coffee Carts rounds: 5-min study-related educational presentations for providers on shift; and a secondary initiative, a Suboxone Champions program, to engage interested providers as study-related peer educators. We used provider referrals to our team as a proxy for study engagement and report the percent change in mean weekly referrals across two PDSA cycles relative to our established referral baseline. RESULTS: A QI approach afforded real-time review of interventions based on research and provider priorities, increasing engagement via mean weekly provider referrals by 14.5% and 49% across two PDSA cycles relative to baseline, respectively. CONCLUSIONS: Our Coffee Carts and Suboxone Champions program are efficient, low-barrier, educational initiatives to convey study-related information to providers. This work supported our efforts to maximally engage providers, minimize burden, and provide life-saving buprenorphine/naloxone to patients at risk of fatal overdose.

RéSUMé: BUT: Nous avons utilisé des approches d'amélioration de la qualité (AQ) pour accroître l'engagement des fournisseurs des services d'urgence (SU) avec l'inscription des participants à la recherche pendant la crise des opioïdes et la pandémie de maladie à coronavirus (COVID-19). Le contexte de ce travail est l'étude Evaluating Microdosing in the Emergency Department (EMED), un essai randomisé offrant de la buprénorphine/naloxone aux patients aux urgences par randomisation à l'induction standard ou au microdosage. L'engagement des fournisseurs est crucial pour le recrutement des participants à notre étude. En anticipant les difficultés à maintenir un engagement à long terme après une baisse de 63 % des recommandations de fournisseurs quatre mois après les inscriptions, nous avons appliqué le Plan-Do-Study-Act (PDSA) cycles d'élaboration et de mise en œuvre d'une stratégie d'engagement visant à accroître et à maintenir l'engagement des fournisseurs de 50 % par rapport au niveau de référence dans les neuf mois. MéTHODES: Notre stratégie de mobilisation était axée sur les tournées de Coffee Carts : des présentations éducatives de cinq minutes sur l'étude pour les fournisseurs sur le quart de travail; et une initiative secondaire, un programme Suboxone Champions, pour mobiliser les fournisseurs intéressés en tant que pairs éducateurs liés à l'étude. Nous avons utilisé les recommandations des fournisseurs à notre équipe comme indicateur de la participation à l'étude et nous avons signalé le pourcentage de changement dans les recommandations hebdomadaires moyennes pour deux cycles PDSA par rapport à notre base de référence établie. RéSULTATS: Une approche d'AQ a permis d'examiner en temps réel les interventions en fonction des priorités de la recherche et des fournisseurs, ce qui a augmenté l'engagement par l'intermédiaire des recommandations hebdomadaires moyennes des fournisseurs de 14,5 % et de 49 % au cours de deux cycles de PDSA par rapport au niveau de référence, respectivement. CONCLUSION: Notre programme Coffee Carts and Suboxone Champions est une initiative éducative efficace et peu contraignante qui permet de transmettre aux fournisseurs des renseignements sur les études. Ce travail a appuyé nos efforts visant à mobiliser au maximum les fournisseurs, à réduire au minimum le fardeau et à fournir de la buprénorphine/naloxone vitale aux patients à risque de surdose mortelle.

A Simulation-Based Assessment of Levetiracetam Concentrations Following Fixed and Weight-Based Loading Doses: A Meta-Regression and Pharmacokinetic Modeling Analysis.

Current recommendations for refractory status epilepticus (SE) unresponsive to benzodiazepines suggest a loading dose of levetiracetam (LEV) of 60 mg/kg to a maximum of 4500 mg. LEV therapeutic drug monitoring can help guide therapy and is garnering increasing attention. The objective of this study is to simulate the probability of target attainment (PTA) of fixed dose and weight-based loading doses of LEV with respect to established therapeutic target concentrations. Meta-regression of the current literature was performed to evaluate the relationship between intravenous LEV loading dose and seizure cessation in refractory SE patients. A previously published pharmacokinetic model was used to simulate the PTA capacity of competing single intravenous dosing schemes (fixed vs weight-based dosing) to achieve maximum (Cpeak) and 12-h (C12h) plasma concentrations that exceed 12 mg/L. The meta-regression indicated that dosage was not a statistically significant modulator of seizure control at dosages between 20 and 60 mg/kg. Stochastic simulations showed all dosing schemes achieved plasma Cpeak >12 mg/L, but C12h levels were <12 mg/L in subjects over 60 kg with a fixed dose ≤2000 mg or in subjects <60 kg with a weight-based dose <30 mg/kg. Dosages of 40 and 60 mg/kg provided ≥90% PTAs across all weights. Using a weight-based loading dose of 40 mg/kg, up to a suggested maximum of 4500 mg, improves the likelihood of achieving a sustained therapeutic drug concentration after the initial LEV dose, whereas fixed <3000 mg may not achieve the desired concentration before maintenance dosing.

Osterix-driven LINC complex disruption in vivo diminishes osteogenesis at 8 weeks but not at 15 weeks.

The Linker of Nucleoskeleton and Cytoskeleton (LINC) complex is a crucial connective component between the nuclear envelope and the cytoskeleton involving various cellular processes including nuclear positioning, nuclear architecture, and mechanotransduction. How LINC complexes regulate bone formation in vivo, however, is not well understood. To start bridging this gap, here we created a LINC disruption murine model using transgenic mice expressing Cre recombinase enzyme under the control of the Osterix (Osx-Cre) which is primarily active in pre-osteoblasts and floxed Tg(CAG-LacZ/EGFP-KASH2) mice. Tg(CAG-LacZ/EGFP-KASH2) mice contain a lox-STOP-lox flanked LacZ gene which is deleted upon cre recombination allowing for the overexpression of an EGFP-KASH2 fusion protein. This overexpressed protein disrupts endogenous Nesprin-Sun binding leading to disruption of LINC complexes. Thus, crossing these two lines results in an  Osx- driven  LINC  disruption (ODLD) specific to pre-osteoblasts. In this study, we investigated how this LINC disruption affects exercise-induced bone accrual. ODLD cells had decreased osteogenic and adipogenic potential in vitro compared to non-disrupted controls and sedentary ODLD mice showed decreased bone quality at 8 weeks. Upon access to a voluntary running wheel, ODLD animals showed increased running time and distance; however, our 6-week exercise intervention did not significantly affect bone microarchitecture and bone mechanical properties.

Prrx1-driven LINC complex disruption in vivo does not significantly alter bone properties in 8-week male mice nor after 6-weeks voluntary wheel running.

The Linker of Nucleoskeleton and Cytoskeleton (LINC) complex serves to connect the nuclear envelope and the cytoskeleton, influencing cellular processes such as nuclear arrangement, architecture, and mechanotransduction. The role LINC plays in mechanotransduction pathways in bone progenitor cells has been well studied; however, the mechanisms by which LINC complexes govern in vivo bone formation remain less clear. To bridge this knowledge gap, we established a murine model disrupting LINC using transgenic Prx-Cre mice and floxed Tg(CAG-LacZ/EGFP-KASH2) mice. Prx-Cre mice express the Cre recombinase enzyme controlled by the paired-related homeobox gene-1 promoter, a pivotal regulator of skeletal development. Tg(CAG-LacZ/EGFP-KASH2) mice carry a lox-stop-lox flanked LacZ gene allowing for the overexpression of an EGFP-KASH2 fusion protein via cre recombinase mediated deletion of the LacZ cassette. This disrupts endogenous Nesprin-Sun binding in a dominant negative manner disconnecting nesprin from the nuclear envelope. By combining these lines, we generated a Prrx1(+) cell-specific LINC disruption model to study its impact on the developing skeleton and subsequently exercise-induced bone accrual. The findings presented here indicate Prx-driven LINC disruption (PDLD) cells exhibit no change in osteogenic and adipogenic potential compared to controls in vitro nor are there bone quality changes when compared to in sedentary animals at 8 weeks. Although PDLD animals displayed increased voluntary running activity, a 6-week exercise intervention did not significantly alter bone microarchitecture or mechanical properties.

Sharing Adverse Drug Event Reports Between Hospitals and Community Pharmacists to Inform Re-dispensing: An Analysis of Reports and Process Outcomes.

INTRODUCTION: Adverse drug events (ADEs) are a leading cause of unplanned hospital visits. We designed ActionADE, an online ADE reporting platform, and integrated it with PharmaNet, British Columbia's (BC's) provincial medication dispensing system, to overcome identified barriers in ADE reporting and communicate ADEs to community pharmacies. Our objectives were to characterise ADEs reported in ActionADE, explore associations between patients' age, sex and ADE characteristics, and estimate the re-dispensation rate of culprit medications in community pharmacies. METHODS: We conducted a prospective observational study of ADE reporting in four BC hospitals between April 1, 2020 and October 31, 2022. We described the characteristics of ADEs reported into ActionADE, used logistic regression modelling to examine associations between age and sex and ADE characteristics, and calculated rates of avoided culprit drug re-dispensations using community pharmacists' responses to ActionADE alerts. RESULTS: In total, 3591 ADE reports were initiated by hospital clinicians, 3174 of which were included in this analysis. Serious or life-threatening ADEs resulting in permanent disability, hospitalisation, extended hospitalisation, and/or death accounted for 28.5% (906/3174; 95% CI 27.0-30.1%) of reports. Males were more likely to have non-adherence reported compared to females and experienced life threatening ADEs at a younger age than females. Of 592 patients who had ≥ 1 adverse drug reaction or allergy report (a subset of ADEs) transmitted to community pharmacies, 200 subsequently attempted to re-fill the culprit or a same class drug. Community pharmacists responded to preventative alerts by avoiding re-dispensation in 33.0% (66/200; 95% CI 26.5-39.5%). INTERPRETATION: ActionADE is the first interoperable system that communicates ADEs via a central medication database to community pharmacies. Every 10th ADE reported in ActionADE and shared to PharmaNet resulted in community pharmacists' avoiding one culprit or same class drug re-exposure. Further research is needed to understand ActionADE's impact on patient and health system outcomes.

Emerging applications of biochar: A review on techno-environmental-economic aspects.

Biomass fast pyrolysis produces bio-oil and biochar achieving circular economy. This review explored the emerging applications of biochar. Biochar possesses the unique properties for removing emerging contaminants and for mine remediation, owing to its negative charge surface, high specific surface area, large pore size distribution and surface functional groups. Additionally, biochar could adsorb impurities such as CO2, moisture, and H2S to upgrade the biogas. Customizing pyrolysis treatments, optimizing the feedstock and pyrolysis operating conditions enhance biochar production and improve its surface properties for the emerging applications. Life cycle assessment and techno-economic assessment indicated the benefits of replacing conventional activated carbon with biochar.

OCCURRENCE OF PATHOGENIC CHYTRID FUNGI BATRACHOCHYTRIUM SALAMANDRIVORANS AND BATRACHOCHYTRIUM DENDROBATIDIS IN THE HONG KONG NEWT (PARAMESOTRITON HONGKONGENSIS) AND OTHER WILD AND IMPORTED AMPHIBIANS IN A SUBTROPICAL ASIAN REGION.

One of the major threats for the massive loss in global amphibian diversity is chytridiomycosis, caused by chytrid fungi Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal). Following its discovery in 2013, Bsal has emerged as a severe threat to the global survival of urodelans. In 2018, a study reported a high prevalence of Bsal (65.6%) in the Hong Kong newts (Paramesotriton hongkongensis, Near Threatened) of a southern China population adjacent to Hong Kong (HK). Uncertainty regarding the Bsal infection status of P. hongkongensis inhabiting HK raised deep concern over the risk of introducing Bsal from that population. We screened the skin swabs from wild individuals of P. hongkongensis, 15 sympatric amphibian species, and 16 imported amphibian species in HK for chytrids. We found that both Bsal and Bd occur in low prevalences in P. hongkongensis (Bsal 1.7%, 5/293; Bd 0.34%, 1/293), Hong Kong cascade frog, Amolops hongkongensis, family Ranidae (Bsal only, 5.26%, 1/19), and Asian common toad, Duttaphrynus melanostictus, family Bufonidae (Bsal only, 5.88%, 1/17), populations of HK, with infected individuals being asymptomatic, suggesting a potential role of these species as reservoirs of Bsal. Conversely, Bd, but not Bsal, was present on 13.2% (9/68) of imported amphibians, indicating a high chytrid introduction risk posed by international amphibian trade. Long-term surveillance of the presence of Bd and Bsal in wild and captive amphibians would be advisable, and we recommend that import and export of nonnative chytrid carriers should be prevented, especially to those regions with amphibian populations naïve to Bd and Bsal.

Osterix-driven LINC complex disruption in vivo diminishes bone microarchitecture in 8-week male mice but not after 6-week voluntary wheel running.

The Linker of Nucleoskeleton and Cytoskeleton (LINC) complex is a crucial connective component between the nuclear envelope and the cytoskeleton involving various cellular processes including nuclear positioning, nuclear architecture, and mechanotransduction. How LINC complexes regulate bone formation in vivo, however, is not well understood. To start bridging this gap, here we created a LINC disruption murine model using transgenic mice expressing Cre recombinase enzyme under the control of the Osterix (Osx-Cre) which is primarily active in pre-osteoblasts and floxed Tg(CAG-LacZ/EGFP-KASH2) mice. Tg(CAG-LacZ/EGFP-KASH2) mice contain a lox-STOP-lox flanked LacZ gene which is deleted upon cre recombination allowing for the overexpression of an EGFP-KASH2 fusion protein. This overexpressed protein disrupts endogenous Nesprin-Sun binding leading to disruption of LINC complexes. Thus, crossing these two lines results in a Osx-driven LINC disruption (ODLD) specific to pre-osteoblasts. In this study, we investigated how this LINC disruption affects exercise induced bone accrual. ODLD cells had decreased osteogenic and adipogenic potential in vitro compared to non-disrupted controls and sedentary ODLD mice showed decreased bone quality at 8-weeks. Upon access to a voluntary running wheel ODLD animals showed increased running time and distance; however, our 6-week exercise intervention did not significantly affect bone microarchitecture and bone mechanical properties.

Evolution of sentinel lymph node biopsy for breast cancer patients in a rural setting: 10 years' experience.

Sentinel lymph node (SLN) biopsy is the standard axillary staging procedure of early breast cancer. Superparamagnetic iron oxide (SPIO) nanoparticles have been found to be comparable to, while overcoming many of the limitations associated with, the current standard of care for SLN biopsies (dual localisation with radioisotope and patent blue dye). Here, SPIO dual localisation (Sienna+® and blue dye) is compared to blue dye alone for SLN biopsies in a rural centre where radioisotope techniques are not readily available. Sienna+® dual localisation is shown to be more likely to detect nodes (detection rate of 99% compared to 90% when using blue dye alone), and detect more nodes, than blue dye alone. The use of Magseed, a magnetic tracer, was not found to influence node detection. The results from this work show that Sienna+® dual localisation is superior to blue dye alone for detecting SLN, suggesting that it is an excellent alternative to dual localisation of radioisotope and blue dye for small centres lacking easy access to a nuclear medicine department.

Human PIK3R1 mutations disrupt lymphocyte differentiation to cause activated PI3Kδ syndrome 2.

Heterozygous loss-of-function (LOF) mutations in PIK3R1 (encoding phosphatidylinositol 3-kinase [PI3K] regulatory subunits) cause activated PI3Kδ syndrome 2 (APDS2), which has a similar clinical profile to APDS1, caused by heterozygous gain-of-function (GOF) mutations in PIK3CD (encoding the PI3K p110δ catalytic subunit). While several studies have established how PIK3CD GOF leads to immune dysregulation, less is known about how PIK3R1 LOF mutations alter cellular function. By studying a novel CRISPR/Cas9 mouse model and patients' immune cells, we determined how PIK3R1 LOF alters cellular function. We observed some overlap in cellular defects in APDS1 and APDS2, including decreased intrinsic B cell class switching and defective Tfh cell function. However, we also identified unique APDS2 phenotypes including defective expansion and affinity maturation of Pik3r1 LOF B cells following immunization, and decreased survival of Pik3r1 LOF pups. Further, we observed clear differences in the way Pik3r1 LOF and Pik3cd GOF altered signaling. Together these results demonstrate crucial differences between these two genetic etiologies.

Correlation of Calculated Vancomycin Trough Concentrations and Exposure: A Monte Carlo Simulation.

BACKGROUND: Current recommendations are to dose vancomycin to target 24-hour area under the curve (AUC) of 400-600 mg·h/L to optimize efficacy and safety. Limited data support AUC monitoring, and some centers continue to use trough concentrations. A target of 10-20 mg/L has been proposed to reduce nephrotoxicity risk. OBJECTIVE: To use previously published pharmacokinetic equations in a Monte Carlo simulation relating AUC exposure to trough concentrations when targeting an AUC between 400 and 600 mg·h/L. METHODS: Previously published pharmacokinetic data were used as input parameters for a Monte Carlo simulation using previously published formulae to correlate AUC to simulated trough concentrations. Pharmacokinetic parameters were assumed to occur in a normal distribution pattern. We excluded irrelevant simulated cases. Maintenance doses of 15 mg/kg were rounded to the nearest 250 mg. Calculated trough concentrations for AUCs of both 400 and 600 mg·h/L were evaluated in each simulation. RESULTS: A total of 10 000 Monte Carlo simulations were performed. Targeting an AUC of 400 mg·h/L resulted in a mean trough concentration of 10.3 ± 0.8 mg/L. Targeting an AUC of 600 mg·h/L resulted in a mean trough concentration of 15.4 ± 1.2 mg/L. CONCLUSION AND RELEVANCE: We demonstrate that a lower trough concentration range may be supported by an AUC of 400-600 mg·h/L, which may reduce risk and rates of nephrotoxicity without compromising previously established efficacious target trough concentrations.

Retinoic acid-gated BDNF synthesis in neuronal dendrites drives presynaptic homeostatic plasticity.

Homeostatic synaptic plasticity is a non-Hebbian synaptic mechanism that adjusts synaptic strength to maintain network stability while achieving optimal information processing. Among the molecular mediators shown to regulate this form of plasticity, synaptic signaling through retinoic acid (RA) and its receptor, RARα, has been shown to be critically involved in the homeostatic adjustment of synaptic transmission in both hippocampus and sensory cortices. In this study, we explore the molecular mechanism through which postsynaptic RA and RARα regulates presynaptic neurotransmitter release during prolonged synaptic inactivity at mouse glutamatertic synapses. We show that RARα binds to a subset of dendritically sorted brain-derived neurotrophic factor (Bdnf) mRNA splice isoforms and represses their translation. The RA-mediated translational de-repression of postsynaptic BDNF results in the retrograde activation of presynaptic tropomyosin receptor kinase B (TrkB) receptors, facilitating presynaptic homeostatic compensation through enhanced presynaptic release. Together, our study illustrates an RA-mediated retrograde synaptic signaling pathway through which postsynaptic protein synthesis during synaptic inactivity drives compensatory changes at the presynaptic site.

PI3K Isoforms in B Cells.

Phosphatidylinositol-3-kinases (PI3K) control many aspects of cellular activation and differentiation and play an important role in B cells biology. Three different classes of PI3K have been described, all of which are expressed in B cells. However, it is the class IA PI3Ks, and the p110δ catalytic subunit in particular, which seem to play the most critical role in B cells. Here we discuss the important role that class IA PI3K plays in B cell development, activation and differentiation, as well as examine what is known about the other classes of PI3Ks in B cells.

Current Treatment Approaches and Global Consensus Guidelines for Brain Metastases in Melanoma.

Background: Up to 60% of melanoma patients develop melanoma brain metastases (MBM), which traditionally have a poor diagnosis. Current treatment strategies include immunotherapies (IO), targeted therapies (TT), and stereotactic radiosurgery (SRS), but there is considerable heterogeneity across worldwide consensus guidelines. Objective: To summarize current treatments and compare worldwide guidelines for the treatment of MBM. Methods: Review of global consensus treatment guidelines for MBM patients. Results: Substantial evidence supported that concurrent IO or TT plus SRS improves progression-free survival (PFS) and overall survival (OS). Guidelines are inconsistent with regards to recommendations for surgical resection of MBM, since surgical resection of symptomatic lesions alleviates neurological symptoms but does not improve OS. Whole-brain radiation therapy is not recommended by all guidelines due to negative effects on neurocognition but can be offered in rare palliative scenarios. Conclusion: Worldwide consensus guidelines consistently recommend up-front combination IO or TT with or without SRS for the treatment of MBM.

Ketamine-precipitated syndrome of inappropriate antidiuretic hormone secretion in a patient with persistent lumbar pain: a case report.

PURPOSE: To report on an unusual case of ketamine-precipitated syndrome of inappropriate antidiuretic hormone secretion (SIADH) in an individual managed by an outpatient pain specialty team. CLINICAL FEATURES: A 78-yr-old male presented to the emergency department with lethargy, malaise, nausea, and abdominal bloating three days following intravenous ketamine infusion for intractable postsurgical lumbar radicular pain with neuropathic features. The patient had a history of resected prostate cancer, hyperlipidemia, chronic kidney disease, and spinal stenosis and the cause of his symptoms was investigated. He was found to be hyponatremic and the treating team excluded reversible surgical and medical causes. A Naranjo score of 7 was calculated, suggesting that the correlation between ketamine and hyponatremia was "likely." Hence, a diagnosis of ketamine-precipitated SIADH was made. The patient was treated with fluid restriction and symptoms were controlled with antiemetics. He returned to baseline function with resolution of the hyponatremia within three days of discharge. CONCLUSION: This case is of clinical importance for providers using ketamine in the field of pain management as the effect of this medication reaction can be profound. Clinicians should develop an awareness that ketamine can potentiate adverse effects such as SIADH and they should monitor, detect, and manage as appropriate.

RéSUMé: OBJECTIF: Nous signalons un cas inhabituel de syndrome de sécrétion inappropriée d'hormones antidiurétiques (SIADH - syndrome of inappropriate antidiuretic hormone secretion) précipité par la kétamine chez une personne prise en charge par une équipe spécialisée en douleur en soins ambulatoires. CARACTéRISTIQUES CLINIQUES: Un homme de 78 ans s'est présenté à l'urgence souffrant de léthargie, de malaise, de nausées et de ballonnements abdominaux trois jours après avoir reçu une perfusion intraveineuse de kétamine pour le traitement d'une douleur radiculaire lombaire postopératoire rebelle avec des caractéristiques neuropathiques. Le patient avait des antécédents de résection de cancer de la prostate, d'hyperlipidémie, d'insuffisance rénale chronique et de sténose du canal rachidien, et la cause de ses symptômes a été évaluée. Il s'est avéré hyponatrémique et l'équipe soignante a exclu les causes chirurgicales et médicales réversibles. Un score Naranjo de 7 a été calculé, suggérant que la corrélation entre la kétamine et l'hyponatrémie était « probable ¼. Par conséquent, un diagnostic de SIADH précipité par la kétamine a été posé. Le patient a été traité par restriction hydrique et les symptômes ont été contrôlés par des antiémétiques. Il est revenu à son fonctionnement de référence avec la résolution de l'hyponatrémie dans les trois jours suivant son congé. CONCLUSION: Ce cas est important d'un point de vue clinique pour les praticiens qui utilisent la kétamine pour la prise en charge de la douleur, car l'effet de cette réaction médicamenteuse peut être profond. Les cliniciens devraient prendre conscience que la kétamine peut augmenter des effets indésirables tels que le SIADH et ils devraient monitorer, dépister et prendre en charge le patient, le cas échéant.

Sex-related differences in aging rate are associated with sex chromosome system in amphibians.

Sex-related differences in mortality are widespread in the animal kingdom. Although studies have shown that sex determination systems might drive lifespan evolution, sex chromosome influence on aging rates have not been investigated so far, likely due to an apparent lack of demographic data from clades including both XY (with heterogametic males) and ZW (heterogametic females) systems. Taking advantage of a unique collection of capture-recapture datasets in amphibians, a vertebrate group where XY and ZW systems have repeatedly evolved over the past 200 million years, we examined whether sex heterogamy can predict sex differences in aging rates and lifespans. We showed that the strength and direction of sex differences in aging rates (and not lifespan) differ between XY and ZW systems. Sex-specific variation in aging rates was moderate within each system, but aging rates tended to be consistently higher in the heterogametic sex. This led to small but detectable effects of sex chromosome system on sex differences in aging rates in our models. Although preliminary, our results suggest that exposed recessive deleterious mutations on the X/Z chromosome (the "unguarded X/Z effect") or repeat-rich Y/W chromosome (the "toxic Y/W effect") could accelerate aging in the heterogametic sex in some vertebrate clades.

FMRP Interacts with RARα in Synaptic Retinoic Acid Signaling and Homeostatic Synaptic Plasticity.

The fragile X syndrome (FXS) is an X-chromosome-linked neurodevelopmental disorder with severe intellectual disability caused by inactivation of the fragile X mental retardation 1 (FMR1) gene and subsequent loss of the fragile X mental retardation protein (FMRP). Among the various types of abnormal synaptic function and synaptic plasticity phenotypes reported in FXS animal models, defective synaptic retinoic acid (RA) signaling and subsequent defective homeostatic plasticity have emerged as a major synaptic dysfunction. However, the mechanism underlying the defective synaptic RA signaling in the absence of FMRP is unknown. Here, we show that RARα, the RA receptor critically involved in synaptic RA signaling, directly interacts with FMRP. This interaction is enhanced in the presence of RA. Blocking the interaction between FMRP and RARα with a small peptide corresponding to the critical binding site in RARα abolishes RA-induced increases in excitatory synaptic transmission, recapitulating the phenotype seen in the Fmr1 knockout mouse. Taken together, these data suggest that not only are functional FMRP and RARα necessary for RA-dependent homeostatic synaptic plasticity, but that the interaction between these two proteins is essential for proper transcription-independent RA signaling. Our results may provide further mechanistic understanding into FXS synaptic pathophysiology.